The World Wide Web has given computer users on the internet access to vast amounts of information in the form of billons of Web pages. Each of these pages can be accessed directly by a user typing the URL (universal resource locator) of a web page into a web browser on the user's computer, but often a person is more likely to access a website by finding it with the use of a search engine. A search engine allows a user to input a search query made up of words or terms that a user thinks will be used in the web pages containing the information he or she is looking for. The search engine will attempt to match web pages to the search terms in the search query and will then return the located web pages to the user.
The search results generated from a user's search query typically consist of a collection of meta-documents, each of which contains summary information, attributes, and other data about the matched documents. These meta-documents are often present in a simple list-based format, displaying the title of the document, a snippet containing the query terms in context, and the uniform resource locator (the URL). A user can then select one of the returned entries to view the corresponding web page.
It is common for web searchers to have difficulties crafting queries to fulfill their information needs. This can result in many, if not most, of the search results not being strongly related to the information the searcher was attempting to find. Even when a searcher provides a good query, he or she often finds it challenging to evaluate the results of their web searches.
With the continued growth of web pages available on the internet making the task of search engines more and more difficult, web search engines have greatly increased the size of their indexes and made significant advances in the algorithms used to match a user's search query to these indexes. However, while it is clear that significant effort has gone into creating web search engines that can index billion of documents and return the search results in a fraction of a second, this has resulted in the creation of the problem of search queries returning more results than the user can easily consider. This is making it even more important to properly craft search queries and to be able to easily evaluate whether a search query has been effective or not.